The present invention relates generally to gas turbine engines, and more particularly to a cooling air scoop for a heat exchanger of a gas turbine engine.
A gas turbine engine typically includes a high pressure spool, a combustion system, and a low pressure spool disposed within an engine case to form a generally axial, serial flow path about the engine centerline. The high pressure spool includes a high pressure turbine, a high pressure shaft extending axially forward from the high pressure turbine, and a high pressure compressor connected to a forward end of the high pressure shaft. The low pressure spool includes a low pressure turbine, which is disposed downstream of the high pressure turbine, a low pressure shaft, which typically extends coaxially through the high pressure shaft, and a fan connected to a forward end of the low pressure shaft, forward of the high pressure compressor. The combustion system is disposed between the high pressure compressor and the high pressure turbine and receives compressed air from the compressors and fuel provided by a fuel injection system. A combustion process is carried out within the combustion system to produce high energy gases to produce thrust and turn the high and low pressure turbines, which drive the compressor and the fan to sustain the combustion process.
The high energy gases contain a substantial amount of thermal energy, which is transferred to the high and low pressure turbines. Therefore, the high and low pressure turbines are cooled using air that is bled from the high pressure compressors. This cooling air can be cooled using a heat exchanger prior to flowing to the turbines in order to maximize the cooling capacity of the cooling air. In such an arrangement, the cooling air flows through the hot side of the heat exchanger, and another fluid must be used for the cold side of the heat exchanger.